The conflict between William Randolph Hearst, the press magnate, and Orson Welles, the greatest filmmaker of all time, over the latter's supposedly Hearst-bashing Citizen Kane is a relatively fascinating story (in the sense that real life is rarely as interesting as art), but there is very little new about it in this documentary.
American arts documentaries are generally inferior to British ones, favouring simplistic generalisations over thoughtful analysis. This film consists of footage and interviews that have mostly been seen before, and offers trite comparisons between Hearst's and Welles' life stories to give their clash a false sense of inevitablity and fatedness, when, as with everything, Welles used the bare bones of Hearst's life (it was Herman Mankiewicz's idea to satirise it in the first place) to film his own tragedy.
If you don't know the story, then this is, I suppose, as good a place as any to start. We get biographical sketches of Hearst and Welles, paralells between their notorious careers, and then the facts of the film's creation and reception. Although you can get all this in any popular encyclopaedia, there is much cherishable footage - e.g. Welles' voodoo Macbeth, the celebrity home movies of San Simeon, Welles' silly beard on arriving in Hollywood - and some splendid eye-witness accounts from William Alland (Thompson in Kane), Ruth Warwick (Mrs. Kane) and Norman Lloyd (a Mercury actor).
The range of interviewees in general, though, is very weak, generally plumping for the obvious (Wise, Bogdanovitch), neglecting contributions from Welles scholars, who might have added some complexity or artistic context to the story. There is little analysis of Kane itself within this biographical context - for this you must turn to David Thomson's exemplary, personality-charged biography, Rosebud.
The film also neglects to ask why, if Kane is such a hack-job on Hearst, why is Charles Foster Kane, monstrous flaws and all, such a rich, sympathetic, frequently awe-inspiring, tragic character, while his model was a despicable, mean-minded fascist? The film's only real insight - that Hearst's sole claim to posterity is his connection with Kane - has been proffered before.
Anyone still intrigued by this story after the film, but looking for something meatier, should check out both the Thomson book, and Welles' extraordinary 1982 BBC interview, several moving chunks of which are interspersed here.